What is this bolt on EJ20 head?

[Dave 53]

2002 WRX EJ20 left side cylinder head. This bolt is leaking oil. It's behind the intake cam pully at about the 11:00 position (looking at the front of the engine). I can't find any reference to it on the internet. Nothing in the FSM. Dealership parts counter guy spent 30 minutes and couldn't find it. It seems to have a rubber washer, so I'm thinking it's a drain plug. I tightened it about an 1/8 turn and leak seems to have stopped - it wasn't torqued very tight. But, I'd like to know what this bolt is for and ideally replace the rubber washer. What is this bolt for? Bonus point if you can come up with a washer part number. Is it part of a head rebuild kit? 141926

PS Turns out it was this bolt leaking oil, not a leaking camshaft seal. The oil found it's way to directly under the camshaft seal and faked me out.

[Sgt.Gator]

That's where your AVCS supply line is supposed to be from the head to the AVCS valve.. Someone has removed it entirely and stuck a bolt in it! The banjo bolt that goes in there has a little mesh screen that is notorious for getting clogged. I've never seen the entire part missing before.

142023....142024.....142025....142026

[Dave 53]

Mystery solved. Thanks! Mine is a 2002 - no AVCS, so I suppose the plug was put in by the factory. Strange that when researching 2002 parts, nothing comes up.